It is quite good. However I'm not happy to see that adding and removing headers are not as convenient as other similar add-ons. I have to type the header name & value (other add-ons allow to select from available lists), and favorite headers are too short, I can't distinguish the favorite ones starting with the same name (like "Content-Type: applicat..."). Besides, if I want to remove a header, I have to remove all of them and add needed ones again. The only thing I like about this add-on is its ability to highlight the response body.